Green’s Dictionary of Slang

bobtail n.2

[the wide skirts of his coat]

1. a dandy.

[UK]J. Ware Passing Eng. of the Victorian Era 40/1: Bobtail (Peoples’). Name given early in the 19th century to the dandies who wore the pointed tailcoats which followed the wide skirts of the 18th century [...] Name still given to a waiter by common classes.

2. a waiter.

see sense 1.